Communication: two-component ring-coupled-cluster computation of the correlation energy in the random-phase...

Area of Science:

• Quantum Chemistry
• Computational Physics
• Relativistic Effects

Background:

• Density-functional theory (DFT) is a powerful tool for electronic structure calculations.
• Accurate computation of correlation energy is crucial for describing chemical properties.
• Relativistic effects become significant for heavy elements.

Purpose of the Study:

• To compute the correlation energy in the random-phase approximation (RPA).
• To investigate the electronic structure of halogen hydrides and coinage metals.
• To implement and validate a two-component relativistic approach.

Main Methods:

• Utilizing density-functional theory (DFT) within the random-phase approximation (RPA).
• Employing two-component relativistic Kohn-Sham calculations including spin-orbit interactions.
• Solving ring-coupled-cluster equations for the two-component RPA correlation energy.

Main Results:

• The two-component RPA correlation energy was successfully computed.
• Results were obtained for hydrides of Br, I, and At.
• Calculations were also performed for coinage metals Cu, Ag, and Au.

Conclusions:

• The developed method provides accurate correlation energies for systems with significant relativistic effects.
• This approach enhances the understanding of electronic properties in heavy elements.
• The study validates the use of relativistic DFT and RPA for molecular calculations.